22. You have an outstanding student loan with required payments of $465.50 per month for the next six years. The interest rate on the loan is 3.75% APR (monthly). You are considering making an extra payment of $134.50 today (that is, you will pay an extra $134.50 that you are not required to pay). If you are required to continue to make payments of $465.50 per month until the loan is paid off, what is the amount of your final payment? What effective rate of return (expressed as an APR with monthly compounding) have you earned on the $134.50? Show your work.

23. Consider again the setting of Problem 22. Now that you realize your best investment is to prepay your student loan, you decide to prepay as much as you can each month. Looking at your budget, you can afford to pay an extra $250 per month in addition to your required monthly payments of $465.50, or $715.50 in total each month. How long will it take you to pay off the loan? Show your work.